Conventionally, in a semiconductor laser device, a joining material is used when bonding a semiconductor chip and the like and a sub mount. When bonding the semiconductor chip, for controlling protrusion of the joining material in a predetermined direction, the sub mount in which a hollow portion is provided such that an area of a bonding surface of the semiconductor chip is made smaller than that of the semiconductor chip and the sub mount has a slope is used. According to this, the joining material protruding when joining the semiconductor chip flows along the slope to be accumulated in the hollow portion, so that the joining material is prevented from protruding on an optical surface of the semiconductor chip and from creeping up (for example, refer to the patent document 1).    Patent Document 1: Japanese Patent Laid-Open Application No. 2000-183439